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GoldenMotor.com

Taz

New Member
Aug 18, 2012
17
0
0
Australia
Hey guys,
Through looking for alternate routes to work as my car is fairly expensive to run/want to keep low km etc i have purchased my first bike motor.
It should arrive any day now - cost 170 from Australia.
Got an 80cc engine, also purchased a 'twin boost bottle' setup (interesting if this works/well) a custom sprocket (smaller for better power) some fiberglass wrap for the exhaust, and a few accessories like torch/spedometer etc.

Through looking at youtube vids and pages of info, im expecting to get a good 50-60km out of it (not sure how much the sprocket affects top speed for power, hopefully doesnt take too much off). Is this about correct?

Also very interested in a sweet nos setup, want to get as much reliable speed out of this thing as possible without shortening the engine life to rebuild/replacement every other month.

I was wondering what else can i do to the motor to get it running smoother/more power. How hard is it to do the head on it? Apprentice mechanic so i have a good mechanical knowledge, although admittedly none on 2 strokes.

Thanks and hope to get this thing up and running nicely to get to work on time!
 

shwnrttr

Member
Dec 2, 2009
336
0
16
38
titusville, florida
welcome to the forum. you should be able to get about 48-52kph,if your running a 26'' wheel with a 44t sprocket. a smaller sprocket will give you more top speed,but reduce acceleration. if you want it to last dont use a nos setup. a simple performance air filter and tuned pipe from(sick bike products) should give you little more power. i would not do much more than that to these 2smokes the more stuff you do to em, the shorter the life span. if your motor has a slant head(angled spark plug) those engines usually have more compression.
 

shwnrttr

Member
Dec 2, 2009
336
0
16
38
titusville, florida
running that dual boost bottle most likely will not improve performance at all.
in order to get any benefit from a boost bottle it needs to be a very specific size according to your displacement size. just like a tuned expansion chamber exhaust. cant hurt to try it though. good luck with your build.let me know if you have any more questions.
 

Taz

New Member
Aug 18, 2012
17
0
0
Australia
Hey,
thanks for the info shwnrttr!
This is the kit i bought
http://www.ebay.com.au/itm/110925139363?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
I have bought a 36T sprocket and wont be on the NOS too much (purchased a kit last night) Moreso for a few of the inclines on the way to work - im aiming to get at least a few months out of the engine - if it goes it gives me an excuse for a 4 stroke build.
I purchased an air filter/spark plug and a few other small things that should hopefully help the engine breathe better.
I have a had a long look through some interesting threads and will definitely tackle match porting and polishing.
With the boost bottle, the kit was for a 60/80cc motor, but from experience does two bottles for this displacement actually increase anything? or am i better using 1 - or better yet fiddling around and testing how many actually work?
I havent purchased the bike yet as i want to make sure that the motor fits in nice and properly, the frame isnt too big/heavy and i get the right bike for the job - what is the best size rim for a good balance between accel - power? Does the type of tyre make that much difference (apart from a road bike which im assuming would yield more speed?) moreso between a BMX/mountain bike tyre.
And one last question (sorry to bombard you guys with these) im assuming that the gears on the bike wont make any difference as i will not be using them? would a bike with less gears be better - less weight/moving parts?

Cheers guys!
 

shwnrttr

Member
Dec 2, 2009
336
0
16
38
titusville, florida
the type of tire will make some difference. but not a whole lot, although i do recommend a wider street tire for more grip in corners. if you have inclines running a 36t might be a little boggy. i would recommend a shift kit from SBPhttp://www.sickbikeparts.com/catalo...ducts_id=86&osCsid=a6i9ac2ro0b8js078i50chv8u4
this will allow you to use your rear derailer and gears. if you do like the shift kit idea keep in mind when buying a bicycle, you do not need one with front gears, so a 7 speed bike will be just the same as a 21 speed bike.
 

Taz

New Member
Aug 18, 2012
17
0
0
Australia
I was looking into the shift kits but i guess the price deterred me from deciding without any kind of knowledge or before i even have the motor in hand.
How affective are they for the cost? Are they going to work like i think they are? (as in, pop into first gear, much better acceleration, pop into last get better top end etc)
I also gen y'd it and said cbf ordering one after i had to type in all my info to join up :lol:

I guess thatll cut costs down a fair bit if im not spending money on a bike with what will become useless gears. Cant wait to start fitting it all to a bike next week - good times ahead hopefully!

And thanks for the helpful hints :)
 

Huffydavidson

STREETRACER/MANUFACTURER
Jan 29, 2012
1,076
4
38
st.louis,mo.
Welcome Taz, I got a shift kit and none of my freinds get me off the line and I'm running a 7speed 14to34 rear Sprocket and no one can catch me. It's the closes you'll get to a motorcycle. Almost 50mph .
 

Taz

New Member
Aug 18, 2012
17
0
0
Australia
Welcome Taz, I got a shift kit and none of my freinds get me off the line and I'm running a 7speed 14to34 rear Sprocket and no one can catch me. It's the closes you'll get to a motorcycle. Almost 50mph .
Hmm then that almost certainly seals it then, we must buy a shift kit!
Cheers!
 

soup325

Member
Dec 11, 2010
181
0
16
Canberra
welcome to the site.

please check the laws at http://motorbicycling.com/showthread.php?t=39266

(zbox link gives state wide info) before you get carried away.

just a caution on those chain idlers that tend to lean in towards the spokes.

- either adjust the chain to the right length, so you can get rid of the idler.
or
buy/engineer a better one that does not move.

there has been many a riders that have had accidents because these.
 
Last edited:

Huffydavidson

STREETRACER/MANUFACTURER
Jan 29, 2012
1,076
4
38
st.louis,mo.
If you don't want to weld it to the frame, then drill 3mm hole all the way threw and put a s.s bolt in it. It won't go any where . Works great on my second bike .
 

Taz

New Member
Aug 18, 2012
17
0
0
Australia
Cheers!

Is this for the shift kits?
Ill have to look into that, but im not fussed welding a bracket on or doing something if it works, last thing i want is an accident at 80kmph!

Tbh, laws dont really fuss me, im pretty sure a nos powered 80cc bike is illegal in QLD, its only really getting me down the road to work and back n cops around here are pretty good, i know a few of em personally as ive lost 49 points in 3 years here (yes yes i know) so as you can see my hunger for speed is insatiable.
 

Taz

New Member
Aug 18, 2012
17
0
0
Australia
So in the hurry of taking apart the bike i just went and picked up to spray it, i find myself very frustrated with putting the front suspension assembly back together - the bearings and handlebar tube etc. I have the bottom bearing in that sits under the fork, and the top bearing which sits on the other side of the shock on top of the bike chassis, but am stuck putting the rest together. Clearly i didnt mark down the order good enough.

I have a seal, a spacer type ring which seems to sit in the top of the other piece which seems as the the bearing runs around - but its already in?
So damn confused and no matter what order i put it in etc the suspension still has wiggle room. It almost seems as though im missing a piece, but ive been very careful and i know only 3 pieces came off the top, which i have accounted for.

Someone please help!
Cheers
 

Attachments

Taz

New Member
Aug 18, 2012
17
0
0
Australia
So just to clarify on the first picture, the top 3 are just spacers, on the left is the top cap that screws down into the suspension.

The bottom left i think is a bearing race, but cannot fit it for the life of me, the middle is a piece that sits on the top of the bearing race (i think) and the right is just a seal.

The other pic is of the bearing already in the tube, which seems to be right.

This is tearing my brains out - im a damned qualified mechanic and cant sort a simple issue like this out =(
 

Ludwig II

Well-Known Member
Jul 17, 2012
5,071
783
113
UK
Going back to the nitrous kit, the best use I can find for it is parties. I had it when I broke my leg, and when it hit, I felt no pain at all and was laughing hysterically. You won't do that if the piston melts.
 

Taz

New Member
Aug 18, 2012
17
0
0
Australia
Long time no post =(

Just waiting on the final order to come from sick bike parts, ordered some goodies including grip shifter, 7 speed freewheel, HD shift kit, a quality bolt/washer kit, air and fuel filter, from another store i purchased a NOS kit.
All that is left is to match port and polish the engine, and put everything on.
Im thinking of getting a forged piston as well as im not sure how much im gonna be on the happy gas, but im assuming its a lot >=D
Finished spraying the bike completely matt black, looks pretty good, only the front shock tube (the bit that actually compresses into the chamber) isnt sprayed, everything else is.
Will post up pics n vides etc when its up and running

Is there any recommended provider for the piston? was looking at wiseco site, not sure if i could source em over here cheaper etc
Cheers